The Furukawa Electric Co., Ltd.

Oplink Technology, Inc.

Nobuyuki Kagi

Masaru Fukushima

Ryo Kawahara

Toru Yoshikawa

Kensaku Sekiya

Koji Yamanaka

Jie Ping Wu

Atsushi Oguri

Masaki Iwama

Kazunori Nakamura

Eisuke Otani

Akira Oyobe

Takeo Okaniwa

Yasumasa Sasaki

Jie Wu

A light operation device includes: an light input and output port; an light-operating element reflecting a light input from any one of the ports of the light input and output port and outputting the reflected light to any one of the ports of the light input and output port; a condensing lens system disposed between the light input and output port and the light-operating element and optically-coupling the light input and output port with the light-operating element; an anamorphic optical system disposed between the light input and output port and the condensing lens system and expanding a beam diameter of the light input from a side of the light input and output port in a beam-diameter-expanding direction. In the condensing lens system, a first focal distance in the beam-diameter-expanding direction and a second focal distance in a direction perpendicular to the beam-diameter-expanding direction differ from each other.

Light operation device

An optical amplifier comprising: a pumping light source supplying a pumping light to an optical fiber as an amplification medium; an ASE light power detector detecting an ASE light power including an external ASE power flowing from an upstream side outside an amplification signal band; and a control unit setting a gain within the amplification signal band by using the ASE light power detected by the ASE light power detector outside the amplification signal band. The control unit controls the pumping light source by compensating for an influence of the external ASE power, obtained by measuring a relationship between the gain within the amplification signal band and the ASE light power outside the amplification signal band, to set initially the gain within the amplification signal band.

Optical amplifier and method of controlling optical amplifier

The present invention provides an optical amplifying apparatus having: a CPUfor processing various signals; a plurality of circuitsfor controlling respective devicesrequired for optical amplification; a first storing unitfor storing a program supplied from a user a gate arrayfor storing various parameters for controlling the devices, the gate array being updated based on the program which is stored in the first storing unitand sent via the CPU; a latch unit, provided between the gate arrayand the circuits, for interrupting a signal path from the gate arrayto the circuitsafter receiving a starting signal of an update from the CPUuntil the update being finished and for controlling the circuitsbased on the parameters stored in the gate arraybefore the signal path is interrupted; and a second storing unitfor, at least during the update, storing the various parameters which are stored in the gate arraybefore the update.

Optical amplifying apparatus

A proportional constant adjusting circuit is arranged in the AGC circuit of the optical amplifying apparatus, and the proportional constant of the proportional circuit is continuously adjusted in correspondence to the optical input power monitored by the PD and the logarithmic transformation circuit. The AGC circuit controls the pump LD based on the monitored optical input/output power so as to control the gain of the optical amplifier to be a requested value.

Optical amplifying method, optical amplifying apparatus, and optical amplified transmission system using the apparatus

An optical amplification apparatus estimates a gain deviation over a range of multiplex wavelength of a signal light received from an EDFA in the preceding stage, selects a gain profile, with which the gain deviation becomes a minimum, from a gain profile storage section, and determines the gain profile. This optical amplification apparatus further controls an HPU (High power pumping light source) according to the determined gain profile and performs Raman amplification on the received signal light.

Optical amplification apparatus and optical transmission system

Optical amplifier and optical wavelength division multiplexing communication system

Quartz glass doped with rare earth element and production thereof

Growing community of inventors

Tokyo, Japan

Nobuyuki Kagi